Do I need to take Plan B?

Hello everyone, I've been on Gildess FE for 3 weeks now. I was supposed to start my period on Sunday. This morning, my significant other came inside of me. I cleaned myself up and went to my classes. I went to the bathroom a few hours later and there were traces of pink on the toilet paper, now it's started to hurt and I'm bleeding more heavily. Do I need to take Plan B and if I do, do I take my BCP normally?